I am using my own convertor. Some times it is not so good, but I've solved the problem for me. It is command line, but it needs qt (I am just to lazy to rewrite it under std and in good way), perl, htmldoc and bash.
Just put chm2html, downlink.pl, chm2pdf.sh files from archive to ~/bin or /usr/local/bin (or some where else in path)
and run:
chm2pdf.sh my-chm-file.chm
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